Ultrasensitive\nAcetone Gas Sensor Based on a K/Sn–Co<sub>3</sub>O<sub>4</sub> Porous Microsphere for Noninvasive Diabetes\nDiagnosis

The detection of acetone in human exhaled breath is crucial\nfor\nthe noninvasive diagnosis of diabetes. However, the direct and reliable\ndetection of acetone in exhaled breath with high humidity at the parts\nper billion level remains a great challenge. Here, an ultrasensitive\nacetone gas sensor based on a K/Sn–Co<sub>3</sub>O<sub>4</sub> porous microsphere was reported. The sensor demonstrates a detection\nlimit of up to 100 ppb, along with excellent repeatability and selectivity.\nRemarkably, without the removal of water vapor from exhaled breath,\nthe sensor can accurately distinguish diabetic patients and healthy\nindividuals according to the difference in acetone concentrations,\ndemonstrating its great potential for diabetes diagnosis. The enhanced\nsensitivity of the sensor is attributed to the increased oxygen adsorption\non the material surface due to K/Sn codoping and the stronger coadsorption\nof Sn–K atoms to acetone molecules. These findings shed light\non the mechanisms underlying the sensor’s improved performance.